The present invention relates generally to vacuum cleaners having at least two cyclonic separation stages.
Various types of vacuum cleaners are traditionally produced. These include built in vacuum cleaners, canister vacuum cleaners and upright vacuum cleaners. Upright vacuum cleaners have a ground engaging portion and an upwardly extending portion. The ground engaging portion typically has wheels for movement of the cleaning head across a floor and a suction inlet for the intake of dirty air into the vacuum cleaner. The upwardly extending portion comprises the filter means for removing dirt which is entrained in the air. The upwardly extending portion generally has a handle for guiding the vacuum cleaner across the floor.
Traditionally in upright vacuum cleaners, the motor to draw the dirty air through the vacuum cleaner is positioned in the ground engaging head and the upward extending portion is pivotally mounted to the upper portion of the ground engaging member at a position adjacent the motor.
More recently, cydonic technology has been introduced commercially into canister and upright vacuum cleaners. See for example U.S. Pat. Nos. 4,373,228; 4,571,772; 4,573,236; 4,593,429; 4,643,748; 4,826,515; 4,853,008; 4,853,011; 5,062,870; 5,078,761; 5,090,976; 5,145,499; 5,160,356; 5,255,411; 5,358,290; 5,558,697; and RE 32,257. These patents disdose a novel approach to vacuum cleaner design in which sequential cyclones are utilized as the filtration medium for a vacuum cleaner. Pursuant to the teaching of these patents, the first sequential cyclone is designed to be of a lower efficiency to remove only the larger particles which are entrained in an air stream. The smaller particles remain entrained in the air stream and are transported to the second sequential cyclone which is frusto-conical in shape. The second sequential cyclone is designed to remove the smaller particles which are entrained in the air stream. If larger particles are carried over into the second cyclone separator, then they will typically not be removed by the cyclone separator but exit the frusto-conical cyclone with the air stream.
The advantages of cyclonic separation have been combined with an upright vacuum cleaner to provide a household cyclonic vacuum cleaner, as shown in U.S. Pat. No. 4,593,429 to Dyson. As shown in FIG. 1, this vacuum cleaner 10 essentially comprises a large, outer cylindrical cyclone 12, with an inner cyclone 14 nested therein, which is mounted on a ground engaging member or floor-cleaning head and provided with a push handle for convenient movement of the unit. A motor, located in the floor cleaning head, draws air through the cleaning head and into an intake conduit 16, which delivers air to the dirty air inlet 18 of the outer cyclone container 12. From the outer cyclone the air flows into inner, nested dust separating cyclone 14, and from there, continues on through the vacuum motor to a dean air exhaust port.
The air intake conduit 16 connects the floor cleaning head and the dirty air inlet in air flow communication. Air intake conduit 16 extends upwardly along the outside of outer cyclone container 12 generally parallel to the longitudinal axis of the cyclones 12, 14. At a position adjacent air inlet 18 to outer cyclone 12, air intake conduit 16 bends 90xc2x0 and travels inwardly to provide a tangential air flow inlet to air inlet 18 of outer cyclone container 12.
In use, air intake conduit 16 may become blockage. If the blockage occurs at a midpoint of the conduit, it may be difficult to clear the blockage. While a clean out port may be provided, the port may not be located near where the blockage occurs. Further, the addition of a port increases the cost and complexity of the manufacture of the product.
A bend in a conduit for a fluid causes a turbulent pressure loss in the conduit as the fluid travels through the bend in the conduit and the greater the sharpness of the bend, the greater the pressure loss. The pressure loss in the air flow decreases the amount of suction which can be generated at the cleaning head of the vacuum cleaner for any given motor in the vacuum cleaner and therefore the efficiency of the vacuum cleaner.
One disadvantage of cyclonic vacuum cleaners is the amount of power which is required to create an air flow sufficient to convey the dirty air through the cyclones at sufficient speeds to maintain the air flowing cyclonically through the cyclones.
In accordance with the instant invention, there is provided an upright vacuum cleaner comprising:
(a) a cleaning head for cleaning a surface;
(b) an upper body portion mounted on the cleaning head, the upper portion having a longitudinally extending axis and comprising:
(i) at least one cyclone having an air entry port; and,
(ii) a motor positioned above the at least one cyclone and in air flow communication with the at least one cyclone.
In accordance with the instant invention, there is also provided an upright vacuum cleaner comprising:
(a) a cleaning head for cleaning a surface having a forward portion and two spaced apart rear portions extending rearwardly from the forward portion;
b) an upper body portion mounted on the cleaning head, the upper portion having a longitudinally extending axis and at least one cyclone having an air entry port, the upper body portion mounted on the cleaning head at a position forward of the spaced apart rear portions, the spaced apart rear portions defining on open space therebetween sized for receiving the upper body portion therebetween when the upper body portion is in the lowered storage position.
In one embodiment, the cleaning head has a forward portion including an opening in air flow communication with the m at least one cyclone and two spaced apart rear portions extending rearwardly from the forward portion, the spaced apart rear portions defining on open space therebetween, the upper body portion mounted on the cleaning head at a position forward of the spaced apart rear portions.
In another embodiment, the upper portion is positionable in a lowered in use position wherein the longitudinally extending axis is at an angle of 40xc2x0 to the vertical and, when the upper body portion is in the lowered in use position, the centre of gravity of the upper body portion is positioned above the open space. The upper body portion may further comprise a handle, the weight of the handle in the lowered in use position being 2 lbs. or less.
The spaced apart rear members may have floor contacting members such as glides or wheels adjacent the ends thereof. The floor contacting members may be positioned rearwardly of the centre of gravity when the upper body portion is in the lowered in use position.
In another embodiment, the upper body portion is pivotally connected to the cleaning head whereby the upper body portion is moveable between an in use position in which the upper body portion extends upwardly and rearwardly from the cleaning head and a lowered storage position in which the upper body portion extends generally rearwardly from the cleaning head. The cleaning head may have a forward portion and two spaced apart rear portions extending rearwardly from the forward portion, the upper body portion mounted on the cleaning head at a position forward of the spaced apart rear portions, the spaced apart rear portions defining on open space therebetween sized for receiving the upper body portion therebetween when the upper body portion is in the lowered storage position.
In another embodiment, the vacuum cleaner further comprises a mounting member engageable with a support member mounted on a wall whereby the vacuum cleaner may be hung flush against the wall when the upper body portion is in the lowered storage position.
In another embodiment, the vacuum cleaner further comprises a second cleaning member positioned downstream from the at least one cyclone.
In another embodiment, the vacuum cleaner further comprises an air outlet to the at least one cyclone for passage therethrough of air, the air passing generally upwardly from the air outlet to the motor.
In another embodiment, the second cleaning member is an electrostatic cleaning member.
In another embodiment, the second cleaning member is positioned between the at least one cyclone and the motor.
In another embodiment, the second cleaning member comprises at least one second cyclone.
In another embodiment, the second cleaning member comprises a plurality of second cyclones.
In another embodiment, the second cleaning member is positioned between the at least one cyclone and the motor, the vacuum cleaner further comprising an air outlet to the at least one cyclone and an air outlet to each of the at least one second cyclones, the air passing generally upwardly from the air outlet to the at least one cyclone to the at least one second cyclones and generally upwardly from the air outlet to the at least one second cyclones to the motor.
In another embodiment, the second cleaning member is positioned downstream of the motor, the vacuum cleaner further comprising an air outlet to the at least one cyclone, the air passing generally upwardly from the air outlet to the at least one cyclone to the motor and generally upwardly from motor to the at least one second cyclones.
In another embodiment, the vacuum cleaner further comprises an air inlet to the at least one cyclone and an air supply conduit communicating with the cleaning head and with the air entry port, a portion of the air supply conduit extending longitudinally through the cyclone. The air supply conduit may connect to the air entry port other than through a 90xc2x0 elbow.